CASCACascade Atlas

Evidence dossier

CVE-2023-43770

Roundcube before 1.4.14, 1.5.x before 1.5.4, and 1.6.x before 1.6.3 allows XSS via text/plain e-mail messages with crafted links because of…

Exploited in the wild (CISA KEV since Feb 12, 2024). NVD reports CVSS 3.1 6.1. EPSS estimates 58.5% exploit likelihood as of Aug 27, 2026.

74.7–78.5Priority evidence range
Evidence current through Aug 27, 2026, 6:09 PM UTC

As of Aug 27, 2026

Normalized restatement

Roundcube before 1.4.14, 1.5.x before 1.5.4, and 1.6.x before 1.6.3 allows XSS via text/plain e-mail messages with crafted links because of program/lib/Roundcube/rcube_string_replacer.php behavior.

State
PUBLISHED
Published
Sep 22, 2023
Updated
Oct 21, 2025
Evidence coverage
91%

Evidence chronology

What was known when

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  1. Source dateSource date omittedFirst observed by CASCA
    CISA-ADP

    Record text: CISA ADP Vulnrichment

    Inspect raw assertion
    Field
    container
    Value
    CISA ADP Vulnrichment
    Original evidence ↗
  2. Source dateSource date omittedFirst observed by CASCA
    CVE Program

    Record text: CVE Program Container

    Inspect raw assertion
    Field
    container
    Value
    CVE Program Container
    Original evidence ↗
  3. Source dateSource date omittedFirst observed by CASCA
    mitre

    Record text: Roundcube before 1.4.14, 1.5.x before 1.5.4, and 1.6.x before 1.6.3 allows XSS via text/plain e-mail messages with crafted links because of program/lib/Roundcube/rcube_string_replacer.php behavior.

    Inspect raw assertion
    Field
    container
    Value
    Roundcube before 1.4.14, 1.5.x before 1.5.4, and 1.6.x before 1.6.3 allows XSS via text/plain e-mail messages with crafted links because of program/lib/Roundcube/rcube_string_replacer.php behavior.
    Original evidence ↗
  4. Source dateFirst observed by CASCA
    CISA KEV

    Exploitation cataloged: Roundcube Webmail Persistent Cross-Site Scripting (XSS) Vulnerability

    Inspect raw assertion
    Field
    observed_exploitation
    Value
    Roundcube Webmail Persistent Cross-Site Scripting (XSS) Vulnerability
    Original evidence ↗
  5. Source dateFirst observed by CASCA
    FIRST EPSS

    EPSS score: 58.48% probability · 99.03th percentile

    Inspect raw assertion
    Field
    model_probability
    Value
    Probability 0.584830000000; percentile 0.990290000000
    Original evidence ↗
ExploitationCatalog member

CISA KEV · catalog date Feb 12, 2024 · first observed Jul 19, 2026

Exploit likelihood58.48%

FIRST EPSS · score date Aug 27, 2026 · 99th percentile · first observed Aug 27, 2026

SeverityCVSS 6.1

NVD · CVSS 3.1 · first observed Jul 19, 2026 · same-version scores align in this snapshot

Evidence detail

Source limits and decisions

Why each evidence state has this value

casca-unknown-reasons-v1
Exploitation statusEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Aug 27, 2026
Resolution
None
Exploit likelihoodEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Aug 27, 2026
Resolution
None
Severity assessmentEvidence supported

Eligible evidence is present for this bounded claim.

Revision
casca-direct-cvss-eligibility-v1
Cutoff
Aug 27, 2026
Resolution
None
Affected productsSource-reported scope

The cited source assertion is retained while canonical product linkage remains open.

Revision
casca-factor-d-obligations-v1
Cutoff
Aug 27, 2026
Resolution
Resolve identity

Source comparison

Who said what

CISA-ADPIndependent enrichment
Record text

CISA ADP Vulnrichment

Inspect raw assertion
Field
container
Value
CISA ADP Vulnrichment
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CVE ProgramDerivative copy
Record text

CVE Program Container

Inspect raw assertion
Field
container
Value
CVE Program Container
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
mitreOriginal assertion
Record text

Roundcube before 1.4.14, 1.5.x before 1.5.4, and 1.6.x before 1.6.3 allows XSS via text/plain e-mail messages with crafted links because of program/lib/Roundcube/rcube_string_replacer.php behavior.

Inspect raw assertion
Field
container
Value
Roundcube before 1.4.14, 1.5.x before 1.5.4, and 1.6.x before 1.6.3 allows XSS via text/plain e-mail messages with crafted links because of program/lib/Roundcube/rcube_string_replacer.php behavior.
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CISA KEVOriginal assertion
Exploitation cataloged

Roundcube Webmail Persistent Cross-Site Scripting (XSS) Vulnerability

Inspect raw assertion
Field
observed_exploitation
Value
Roundcube Webmail Persistent Cross-Site Scripting (XSS) Vulnerability
Source dateFirst observed by CASCAOriginal evidence ↗
FIRST EPSSOriginal assertion
EPSS score

58.48% probability · 99.03th percentile

Inspect raw assertion
Field
model_probability
Value
Probability 0.584830000000; percentile 0.990290000000
Source dateFirst observed by CASCAOriginal evidence ↗

Applicability

Cited product scope

Trace impact →
4Underlying assertions
2Canonical products
4Target assertions
0Constraint assertions

Grouped from 2 configuration nodes in this exact snapshot. Visual grouping is navigational; asset exposure and root cause require cited evidence.

Identity source boundaries
  • Cpe dictionary1,775,266 records · observed through 2026-07-21T06:45:29.809Z27d65b0f-b718-4b4f-bb79-c47c68d09dfa
  • Cpe match643,502 records · observed through 2026-07-21T08:13:17.697Z955dae73-7302-438b-aee1-058d7cc5d48e

7 scope groups

CISA-ADP · source asserteddebiandebian_linuxDirect source scope
Affected: 10
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "10"}]
mitre · source assertedn/an/aDirect source scope
Affected: n/a
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "n/a"}]
CISA-ADP · source assertedroundcubewebmailDirect source scope
Affected: 0 to before 1.4.14 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "0", "lessThan": "1.4.14", "versionType": "custom"}]
CISA-ADP · source assertedroundcubewebmailDirect source scope
Affected: 1.5.0 to before 1.5.4 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "1.5.0", "lessThan": "1.5.4", "versionType": "custom"}]
CISA-ADP · source assertedroundcubewebmailDirect source scope
Affected: 1.6.0 to before 1.6.3 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "1.6.0", "lessThan": "1.6.3", "versionType": "custom"}]
NVD CPE · OPERATING SYSTEMdebiandebian_linuxVulnerable target · 1 assertions
Version 10.0Canonical identity product-3ccb4bc87dfae98fa2f2a06435fe5b3d9be78572fb958a89f2d7a96b4066447eLinked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    07b237a9-69a3-4a9c-9da0-4e06bd37ae73
NVD CPE · APPLICATIONroundcubewebmailVulnerable target · 3 assertions
Any version (unconstrained) (< 1.4.14); Any version (unconstrained) (>= 1.5.0, < 1.5.4); Any version (unconstrained) (>= 1.6.0, < 1.6.3)Canonical identity product-76727fe8712c90ab91dda56c7c24f60395233b4574759c51ef434d53d08d9bf1Linked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:a:roundcube:webmail:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 1
    Logic
    OR
    Version bounds
    from including 1.5.0; through excluding 1.5.4
    Match ID
    772ec31f-eac3-455e-953f-8fc04ea2a186
  2. cpe:2.3:a:roundcube:webmail:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 0
    Logic
    OR
    Version bounds
    through excluding 1.4.14
    Match ID
    98f5df3c-3ca0-4e0f-9c8a-7b18f3aedb77
  3. cpe:2.3:a:roundcube:webmail:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 2
    Logic
    OR
    Version bounds
    from including 1.6.0; through excluding 1.6.3
    Match ID
    463446a7-da28-41d3-b358-fa3bebd6397e

Affected-product evidence

Accepted scope and product mapping

2 canonical links · 1 source-reported links

Mapping establishedEvidence supported

vendor-66ae8c5e06427f7450637d18322b0dc411c0b469d940341cf076a620d444fe3c · product-3ccb4bc87dfae98fa2f2a06435fe5b3d9be78572fb958a89f2d7a96b4066447e

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
d82b64ce-66e1-44e9-becf-ddd21260a1ba
Mapping establishedEvidence supported

vendor-04bf25ab3cb69267d5aa67724fc5a03de405b94e7e220256a10f771f2ee0a46f · product-76727fe8712c90ab91dda56c7c24f60395233b4574759c51ef434d53d08d9bf1

Source class
Nvd cpe vulnerable target
Assertions
3
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
cdf2f253-f8f5-4920-99a7-c6a538d6ecd1e99bdc76-5ae6-4be5-b9a6-d72fff28bbceec901c93-3482-4cd7-abdf-51a44fbdb46d
Source-reported scopeSource-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Vendor specified only by source · Product specified only by source

Source class
Direct cve affected
Assertions
5
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
0e89f940-51a9-46ba-a5e8-bbce4c9a368c66a0aaea-1248-4ea9-b69b-4d67896af20484309e91-03e5-4eaa-9436-f0445badb36985239514-c24b-4a7b-87f4-262a8a7ac7b39cde31ad-02b2-471d-9f7a-ec70f63cd23b

Assessments

CVSS by origin

6.1
NVDCVSS 3.1 · role Primary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
6.1
CVE Program sourceCVSS 3.1 · role Secondary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
6.1
CISA-ADPCVSS 3.1 · role unknown · display onlyDirect record assessment retained outside normalized eligibilityCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Direct CVE/CNA normalized decisions

6.1Priority eligible

CISA-ADP

CVSS 3.1 · Secondary · Independent enrichment · rank 2

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Validation
Valid match
Recomputed
6.1
Decision reason
Evidence supported
Policy
casca-direct-cvss-eligibility-v1

Assessments are retained side by side under closed precedence. Cascade never averages CVSS.

Evidence boundaries

  • KEV membership is authoritative for the catalog, not proof of exposure in any environment.
  • EPSS is a dated model probability and not an individual-environment prediction.
  • Affected or fixed status applies only to the exact cited product and version scope; remaining scope stays source-scoped.
  • NVD-carried upstream facts remain derivative; independent corroboration requires a separately authored source.
  • Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
  • NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.
  • OSV aggregation and OSV-converted NVD material are not independent corroboration.
  • Red Hat facts are vendor assertions for the exact supplied products.
  • Nonmembership and not-yet-observed states are not proof of safety.